The present invention relates generally to a thermal food treatment system which is capable of refrigerated storage and rethermalization of food. More particularly, the present invention relates to a novel rethermalization system comprising: (1) a food refrigeration/rethermalization cart; (2) a thermal barrier system; and (3) a docking station that provides refrigerated and heated air to the refrigeration/rethermalization cart.
The preparation and service of large numbers of meals in an institutional setting has long posed a variety of problems. The ability to serve palatable meals with the various dishes being served at optimum temperature often conflicts with efforts to make service of the meals easier, more efficient and less manpower intensive.
The preparation, storage, rethermalization and service of a large number of meals have evolved through several stages. Initially, trays would be filled with food from various hot or cold storage container areas just prior to serving and transported to the individual serving areas (such as patients rooms in a hospital). However, as facilities grew larger, the assembly of trays from a centralized area became very difficult if not impossible. Frequently, in such systems the time between tray assembly and service grew longer, resulting in food being served at an unpalatable temperature or with spoilage occurring.
Early attempts to overcome such problems resulted in the development of storage carts having separate rethermalization and refrigeration storage compartments. These separate compartments would either be heated or cooled or would be well-insulated in order to maintain the food at a desired temperature. In use, food would be loaded into separate rethermalization and refrigeration storage compartments at a central food preparation area. The carts would then be transferred to various assembly locations. The individual meals could then be assembled on trays as desired and served. However, while such delivery systems did improve the time lag between assembly of the trays and service of the meal, they still required significant manpower at serving time because these trays had to be assembled. As a result, frequently food, which was intended to be warm when served would be heated for extended periods of time and would thus become unpalatable. In the alternative, if all trays were assembled at once, some of the heated food would cool by the time it was served and would also become unpalatable. Additionally, meal service times would be extended over the time required to assemble the trays. Furthermore, in prior art delivery carts having separated chilled and heated food storage compartments, the size and number of rethermalization and refrigeration storage compartments were fixed and could not easily be adjusted.
Another development was a food service system of trays and carts incorporating heating elements for rethermalization of refrigerated foods. The food was located on trays and kept in a refrigerated environment until the rethermalization cycle was initiated. In this type of system, trays could be pre-assembled whenever desired and loaded into the carts. In the refrigerated environment food would remain cold. At a desired time, heating elements would be activated, perhaps through computer programming, to rethermalize the food and to maintain the warm food in a warm condition while not effecting the temperature of food in the chilled compartments. After the food had reached a serving temperature the carts could then be rolled to the service locations and the trays served. However, such prior art systems required heating elements selectively place in the cart or in the tray in the areas corresponding to the food that would be heated. This need for specific placement of the heating element in the cart and/or tray increased the manufacturing and maintenance costs of the cart and/or tray.
U.S. Pat. No. 5,655,595 to Westbrooks, Jr., assigned on its face to Standex International Corporation, discloses a tray system for an integrated rethermalization/refrigeration cart (hereinafter xe2x80x9cthe Westbrooks tray systemxe2x80x9d). The Westbrooks tray system includes a tray (hereinafter xe2x80x9cthe Westbrooks trayxe2x80x9d) having a first section for storing cold food and a second section for storing hot food. In the Westbrooks tray system, the Westbrooks tray has a flat ridge that is inserted into a gap created between two dividers affixed to the cart. The gap between the two dividers is a fixed distance and the tray ridge must be configured to fill the gap in order to provide the necessary thermal barrier between the heated and refrigerated sections. The Westbrooks tray system is unforgiving with respect to the mating of the tray with gap. If the tray is too thin in comparison to the width of the gap, an adequate thermal barrier will not form. If the tray is not thin enough, the food service worker must exert extra care and effort to position the tray within the gap, if insertion is even possible. Furthermore, the Westbrooks tray system requires that a tray be inserted between each pair of dividers in order to maintain the necessary thermal barrier between the refrigerated section and the rethermalization section. Since every gap requires tray insertion, the Westbrooks tray system fails to provide flexibility with respect to the number and vertical size of heated and refrigerated storage sections provided.
The Westbrooks patent also describes a rethermalization system that includes a docking unit. The Westbrooks rethermalization system has one supply conduit to the food cart rethermalization compartment. This single supply conduit is used to first provide refrigerated air to the rethermalization compartment during the refrigeration cycle and then to provide heated air during the rethermalization cycle.
There is a need for a rethermalization system which can (1) handle adjacent rethermalization and refrigeration compartments within a single delivery cart, (2) a thermal barrier between such rethermalization and refrigeration compartments which is adjustable in both quantity and size, and (3) a cost-effective design for carrying out the dual refrigeration and rethermalization function without having to provide individual heating and refrigeration elements to each separate compartment within the delivery cart.
The present invention provides a novel thermal food treatment system that provides a novel air flow system from a docking unit through a delivery cart having a refrigeration section and a rethermalization section.
In one aspect of the invention, a thermal treatment apparatus is provided that includes a thermal treatment section having a plurality of individual thermal treatment sections. The apparatus further includes. (a) an air supply duct with at least one supply port associated with each said individual thermal treatment section through which temperature controlled air passes into each said individual thermal treatment section and (b) at least one air return port for each individual thermal treatment section through which said temperature controlled air exits the individual thermal treatment sections. In a preferred embodiment of the above-described invention, a barrier is provided between each individual thermal treatment section, preferably in the form of a removable food tray.
In another preferred embodiment of the invention, the thermal treatment apparatus includes a second thermal treatment section also having a plurality of individual thermal treatment sections and further includes (a) a second air supply duct with at least one supply port associated with each of the individual thermal treatment section of the second thermal treatment section through which temperature controlled air passes into each said individual thermal treatment section, and (b) at least one air return port for each individual thermal treatment section of the second thermal treatment section through which temperature controlled air exits.
In yet another preferred aspect of the invention, the thermal treatment apparatus the air supply duct has a novel design including an upper end, a lower end and an inlet opening between said upper and lower ends in fluid communication with a blower. The air supply duct has a plurality of air supply ports through which air may exit the duct into the thermal treatment section. The duct comprises (a) a first tapered upper portion adjacent the inlet opening and a second tapered upper portion adjacent the upper end, with the first tapered upper portion having a greater angle of taper than the second tapered upper portion, and (b) a first tapered lower portion adjacent the inlet opening and a second tapered lower portion adjacent the lower end, with the first tapered lower portion having a greater angle of taper than the second tapered lower portion. In another preferred embodiment of the invention an adjustable diverter is provided adjacent the inlet opening to control the amount of air supplied to the upper and lower ends of the air supply duct.
The present invention also provides a novel air flow system that during a first or refrigeration cycle provides refrigerated air to both the refrigeration section and the rethermalization section, but then during a second or rethermalization cycle provides refrigerated air to the refrigerated section while providing heated air to the rethermalization section.
The present invention also provides a novel thermal barrier system between the refrigeration and rethermalization compartments of the food delivery cart. That is, the novel cart according to the present invention that has a rethermalization storage compartment adjacent to a refrigerated storage compartment which has a removable self-adjusting sealing mechanism between the two storage compartments so as to provide a thermal barrier between the adjacent rethermalization and refrigerated storage compartments. This unique food delivery cart also include rethermalization and refrigerated storage compartments that are adjustable in both vertical height and number of compartments per cart.